Hydraulic Deep Draw Forming
The new development technology of the basic process of flushing deep drawing:
On the basis of the basic technology of liquid flushing deep drawing, new technologies such as radial pressure liquid filling deep drawing, radial pressure liquid filling reverse drawing, thinning liquid filling deep drawing and differential temperature liquid filling deep drawing have been developed.
1) Radial pressurized liquid-filled deep drawing method:
The radial pressurized liquid-filled deep drawing method is based on the liquid-filled deep-drawing process, and an additional liquid hole is set so that the liquid pressure in the liquid-filled chamber acts on the outer edge of the broken material, and the radial pressure can improve the stress on the deformation zone. In this case, reduce the load in the force transmission area and increase the allowable deformation degree from the surface. In addition, in the aforementioned basic process of liquid-filled deep drawing, the liquid only flows out from the lower side of the flange, and the upper surface of the flange does not form ideal lubrication, while the radial pressurized liquid-filled deep drawing makes both sides well lubricated State, which is also an important factor to promote the degree of deformation.
2) Radial pressurized liquid-filled reverse drawing:
Radial pressurized liquid-filled reverse drawing is the extension and expansion of radial pressurized liquid-filled deep drawing to reverse deep drawing. A few more side holes are opened on the mold, and a seal is added to guide the pressure of the liquid chamber to the outer periphery of the drawn part. The advantage of this process is that it can further increase the overall degree of deformation through reverse drawing and reduce the total number of drawing passes; the disadvantage is that the mold structure is complex. This method is suitable for the forming of ultra-deep cylindrical parts and complex tapered parts.
3) Thinning liquid-filled deep drawing:
Thinning liquid-filled deep drawing is to effectively apply liquid-filled medium to thinning deep drawing. According to different liquid filling methods, it can be divided into reverse thinning liquid filling deep drawing, forward thinning liquid filling deep drawing and two-way thinning liquid filling deep drawing. All three methods can effectively increase the limit deformation degree of thinning and deep drawing, among which the positive direction and bidirectional direction are better. In addition, thinning liquid-filled deep drawing has a significant inhibitory effect on the mold thermal sticking phenomenon that often occurs in traditional thinning deep drawing, and is especially suitable for thinning stainless steel deep drawing to improve surface quality.
4) Differential temperature liquid-filled deep drawing:
Differential temperature liquid-filled deep drawing is to firstly press the blank holder against the die filled with liquid medium, heat the die and the blank holder, lift the blank holder after heating to a certain temperature, put the blank, and close After the mold is kept warm to the set temperature, the punch goes down for deep drawing, and at the same time, the punch is cooled by circulating water to reduce the temperature of the punch. The advantage of this process is that the internal factors of reducing the deformation resistance of the material in the flange deformation area through differential temperature drawing are combined with the external factors of fluid lubrication and beneficial friction in liquid-filled deep drawing, and further improve the relative strength of the ring material at the punch fillet. Load carrying capacity, thereby increasing the forming limit. Due to the limitation of the heat-resistant temperature of the liquid medium, it is suitable for forming materials such as aluminum alloy, magnesium alloy and stainless steel at a low temperature (below 300°C). The main disadvantages are complex process, low efficiency and high mold cost.
